Originally Posted by
Skyblade
Thinking about it... I'm not sure these guys are the villains.
They're too small. The scale isn't there. From what we can tell, they're a group that banded together because they were strong Trainers who were passed over for the Trial Captain positions. Which makes it sound like they don't like the Trial system. Which, with the leaks looking more and more accurate, could fit into the story of setting up a League in Alola, which would replace the Trials. I could totally see Team Skull winding up as a Gym, with the Big Sister as a Gym Leader, and maybe the Big Boss as an Elite Four member?
But it just looks like they have a gripe with the current system, and are going to block and hinder you along the Trials (the Japanese trailer shows them blocking routes and such). This is decidedly small-scale compared to every other Team, including Rocket.
I think that, like Team Snag'Em in the GameCube games, they may simply be a red herring from the real villains who are plotting something much worse. And they may even help out when it comes down to it.